Sorting apparatus



Dec. 26, 1933. M. N. RICH SORTING APPARATUS Filed July so, 1950 2 Sheets-Sheet l INVENTOR Malcolm N. Rich.

v ATTORNEY Dec. 26, 1933. M. N. RICH SORTING APPARATUS Filed Ju ly so, 1950 2 Sheets-Sheet 2 INVENTOR Malcolm Rich.

ATTO'RNEY Patented Dec. 26, 1933 SORTING' APPARATUS Malcolm N. Rich, East Orange, N. J., assignor to Westinghouse Electric 80 Manufacturing Comvpany, a corporation of Pennsylvania Application July 30, 1930. Serial No. 471,669 1 Claim. (Cl. 209 -111) My invention relates to improvements in article-sorting systems and has particular relation to photo-sensitive sorting systems.

Photo-sensitive sorting apparatus, constructed 5 and operated according to the teachings of the prior art with which I am familiar, generally comprises a source of light of requisite geometric structure, whereby the surface of the test article is illuminated and a photo-sensitive device responsive to the light transmitted through, or

reflected from, the article.

Systems of this type have the disadvantage that the rays of light, impinging upon each point of the photo-sensitive surface, come from all points of the surface of the test article, and, consequently, the percentage of change in illumination, arising from a defective region in the surface of the test article, is comparatively'smalL- unless the region is large.

Inv experimenting with sorting systems constructed as taught by the prior art, I have experienced considerable difliculty in attaining the requisite response from the photo-sensitive device, and, as a matter of fact, I have found it 26 virtually impossible to construct a device of consequential commercial utility.

It is, accordingly, an object of my invention to provide photo-sensitive sorting apparatus wherein the radiant energy, modified by each element 30 of a surface of an article under test, shall coact,

independently of the other elements of the surface, with a photo-sensitive device.

Another object of my invention is to provide photo-sensitive sorting apparatus wherein each element of the surface of an article under test shall be illuminated substantially from an independent source and shall be independently influential in actuating a signalling or a separating system.

Still another object of my invention is to provide photo-sensitive sorting apparatus wherein the percentage change in the impedance of a photo-sensitive system, under the influence of the light emanating from a test article, by reason 15 of an existing heterogeneity in the surface of the test article, shall depend only upon the condition of the element of the surface of the article whereon the heterogeneity exists.

A more specific object of my invention is to provide photo-sensitive apparatus that shall be capable of sorting articles having a comparatively small surface to present to the beam exciting the photo-sensitive cell that operates the mechanical sorting system.

5 Another specific object of my invention is to provide sorting apparatus for detecting comparatively small heterogeneity in articles.

More concisely stated, it is an object of my invention to provide article-sorting apparatus of compact and simple structure wherein the, percentage of change arising in the electromagnetic energy, of an electro-mechanical article-separating contrivance, by reason of the existance of a heterogeneity in the surface of an article, shall be dependent only on the condition of the individual element of the surface where the heterogeneity exists and on no other element.

According to my invention, I provide sorting apparatus wherein the individual elements of the surface of an article under test are illuminated by independent parallel beams, each beam impinging on the sensitive surface of one of a group of photo-sensitive devices, connected in series relationship.

Since cells ordinarily have dimensions of considerable magnitude, I provide, in the system, a device whereby the individual rays are diverged after they have impinged on the test plate. The optical elements of my improved sorting system are thus adjusted in such manner that each beam so impinges on at least one cell. I

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claim. The invention itself, however, both as to its organization and its 35 method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments, when read in connection with the accompanying drawings, in which:

Figure 1 is a view, in perspective, showing a preferred embodiment of my invention,

Fig. 2 is a schematic view showing the elec-- trical elements of the photo-sensitive inspection eye,

Fig. 3 is a view, in section, taken through the container of the photo-sensitive inspection eye and showing the principal elements thereof,

Fig. 4 is a plan view of the optical system shown in Figs. 3 and 5, and

Fig. 5 is a view, in side elevation, of a modification of my invention.

The apparatus shown in Fig. 1 is, in essence, described in a copending application to V. K. Zworykin, Serial No. 199,392, filed June 16, 1927 and assigned to Westinghouse Electric 8; Manufacturing Company.

The system illustrated in the view comprises a base plate 1 of substantially transverse C-section, from the flanges 3 of which a plurality of ears 5 rotating under and 7 project. The ears and 7 are disposed vis-a-vis to each other in pairs, a plurality of rollers 9 and 11 being mountedbetween certain of the pairs of ears 5. The rollers 9 and 11 are so spaced from each other that the test article 13 (in the present instance, a plate) may pass between them and be engaged by them.

The lower rollers 11 are driven from a prime mover 15 through a system of belts 17 and, in

the test plate 13, propel it forward. v

The remaining ears 7 have a guide-plate 19 mounted pivotally between them to be operated from a rod 21 that is fastened to the core 23 of a relay 25, as will be explained hereinafter. In its horizontal position, the innerv edge of the guide-plate 19 is adjacent to the, two end rollers 9 and 11 and is so disposed, relative thereto, that a test plate 13, as it is propelled by the roller, passes over the surface of the guide-plate.

On the other hand, in its inclined position, the guide-plate lies parallel to a second, and fixed, guide-plate 27 that projects into a slot 29, milled in the end of the base plate 1. In this position,

the upper end of the pivoted guide-plate 19 projects above the lower roller 11 and, consequently, the test plates 13 pass between it and the lower guide-plate 27.

' A plurality of brackets 31 are supported on the flanges 3 of the base plate 1, and a container 33, wherein are disposed the elements of the photosensitive inspection eye, is contained therein; An amplifier 35 and a source of power 37 are disposed adjacent to the container 33 and are conductively connected to the requisite elements therein by a plurality of leads 39 and 41 that are projected into the container through a plurality of openings 43 and 45.

The output current of the amplifier 35 feeds 7 into the exciting coil 4'7 of a relay 49, equipped with a contactor 51 that is capable of closing a circuit 53, in parallel with the exciting coil 55 of the guide-plate relay 25. When the shunt circuit 53 is closed, the current through the exciting coil 55 of the relay 25 is reduced and, as a result, the relay 25 is deenergized.

The contactor 51 is held in open position by a tension spring 57 and closes the shunt circuit 53 only when the exciting coil 47 of the relay 49, associated with the amplifier 35, is energized. The latter condition is attained, as will be explained hereinafter, when a heterogeneous spot in the surface of the article 13 under test comes under immediate inspection of the photo-sensitive scrutinizing eye.

It is seen that, when the shunt circuit 53 is closed and the guide-plate relay 25 is deenergized, the guide-plate 19 is pivoted to its inclined position, and, consequently, the test plate 13 that has caused the motivation of the guide-plate 19 .is transmitted along a channel different from the channel provided for it if it is of such condition as not to excite the relay 49. In the latter case, the guide-plate 19 is in a horizontal position and thetest plate 13 passes over it.

Since the passage ofa spot in the plate 13, under the scrutinizing eye of the'photo-sensitive device, is substantially instantaneous, while the passage of the plate 13 to either of the containers provided therefor is a matter of considerable time, a device must be provided for holding the guide-plate 19 in its inclined position during the time occupied by the plates 13 in passing between it and the lower guide-plate 27. For this reason, a contactor 59 is fastened to the core 23 of the guide-plate relay 25 to close a second circuit 61 for shunting the exciting coil 55 of the relay 25 when the guide-plate 19 is pivoted to its inclined position. The guide-plate relay 25 is thus locked out in its deenergized condition.

To provide for the return of the pivoted guideplate to its horizontal position, after an imperfect plate has passed into the container provided therefor, the latter shunt circuit 61 is provided with a switch 63 comprising a flexible contact 65 that is adapted to be disengaged from a fixed contact 67 by a dog 69 that rotates in synchronism with the movement of the test plates 13. The period of the dog 69 is equivalent to the time occupied by the plate 13 in passing between the photo-sensitive inspection device and the separating receptacle.

In Fig. 2, the electrical circuit of the photosensitive device is shown.

A plurality of photo-sensitive cells 71 are connected in series relationship to feed into a resistance-coupled thermionic amplifier 73 of a type well known to those skilled in the art. The output voltage of the amplifier 73 is impressed between the control electrode 75 and the anode 77 of a grid-glow tube 79. The exciting coil 47 of the relay 49, associated with the amplifier 35, is connected in the anode-cathode circuit of the tube 79 and is energized when the tube 79 is in an excited state. The cells are illustrated as arranged in staggered relationship as they are disposed in the apparatus. The reason for the particular arrangement of the cells will be explained presently.

In operation, the grid-glow tube 79 is in a deenergized condition so long as the cells 71 are energized. However, as soon as a single cell is deenergized, the tube breaks down, and the relay 49, associated therewith, is energized, causing the shunt circuit 53 to close, and the guideplate relay 25 to become deenergized. The guideplate is then pivoted to an inclined position to provide the necessary channel for the imperfect test article.

It is to be noted that the specific form of amplifier shown herein is of the alternating-current type and that, therefore, the light beam should fluctuate periodically in intensity. The fluctuations may be produced by such well-known devices as a light chopper.

In Fig. 3, the elements of the scrutinizing eye are shown in detail.

Light from an elongated source 81 is subdivided in a plurality of rays, collirnated and projected upon the surface of a plate 13 that is under test. The beam reflected from the plate 13 impinges on the surface of a convex cylindrical reflector 83, whereby it is diverged. The light emanating from the reflector 83 is projected on the cathodes 85 of the photo-sensitive cells 71 that are connected to the amplifier 35, as is 11- lustrated in Fig. 2.

It will be noted that, in Fig. 4, the subdivision of the rays and the manner in which they affect the photo-cell is particularly well illustrated. Each individual bundle of rays from the source 81 impinges on a single cell 71 or on a group of cells. Since it is desirable that all of the rays from a bundle shall affect the photosensitive surface of the particular cells with which the pencil is associated, the cells are arranged in staggered relation. If desired, each pencil of rays may be made to influence a group of cells arranged in parallel relationship, while the totality of groups are connected in series.re-' lationship.

It is seen that, by arranging the system as has been described hereinabove, each cell or each group of cells responds only to the condition of the region of the surface with which it is associated.

A specular surface 8'7 is disposed directly beneath the test plates 13 to reflect light into the reflector 83 in the interval occupied between the passage of the test plates 13 under the light beam.

The function of the cylindrical reflector 83 is to substantially magnify the surface of the article 13, that is inspected, in the direction in which the light beam extends over it. Where it is possible to deflect the plates 13 that are inspected, the cylindrical reflector 83 is not necessary, since the plates themselves may be bent into the requisite convex form.

Furthermore, for testing articles wherein the allowable fiaw is comparatively large, it is possible to so separate the individual rays impinging on the surface of the articles that the convex reflector 83 is unnecessary.

It is, moreover, well to point out that the surface illuminating device should only be regarded as symbolical. I have found that my apparatus can be applied with singular success when an illuminating device of the scanning type, described in a copending application to V. K. Zworykin, Serial No. 471,668, filed July 30, 1930, and assigned to Westinghouse Electric 8: Manufacturing Company, is utilized.

If a scanning device is utilized in lieu of an elongated source, the cells should be arranged in parallel relationship rather than in series relationship, but they should also be staggered in such manner that the cathodes overlap.

In Fig. 5, a modification of my invention, that- I have found useful in the inspection of comparatively large articles, is shown.

The article is disposed on a car 89 that is propelled along the track 91 in any manner that may be found desirable. The surface of the article 13 is illuminated from a plurality of beams emanating from an elongated source 81 and collimatedinthroughapliu'alityofchannels 93 fixed to the housing 95, wherein the source 81 is contained. The beam reflected from the plate 13 is diverged to impinge upon a plurality of photo-cells 71 in the same manner as the beam of apparatus of the type described hereinabove.

The output of the amplifier 35 associated with the cells 71 may be connected to a relay which actuates a switching arrangement on the tracks and provides for guiding the cars 89 to separate stations, in accordance with the condition of the plate 13 disposed thereon.

As described hereinabove, my invention has been illustrated as applied to specific forms of sorting apparatus. It has also been shown as operated through a specific form of amplifier. It is understood that these details should in no way restrict the scope of my invention, as its application to other types of sorting equipment wherein other types of amplifiers are utilized is obvious.

Furthermore, although my invention has been shown as applied to opaque articles, its application to transparent objects is apparent and is within the scope of my invention.

Although I have shown and described certain speciflc embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not tube restricted except insofar as is necessitated by the prior art and by the spirit of the appended claim.

I claim as my invention:

Article-sorting apparatus comprising a light source, means for directing a plurality of parallel light'beams from said source on the article to be sorted, means for receiving the parallel light beams reflected from said article, said last mentioned means reflecting and laterally diverging said light beams, a plurality of serially connected light sensitive devices arranged in staggered relationship for receiving said light beam, and means for guiding the path of said article in response -to the light beams received by said 

